My original battery has been getting weaker the past few months, so I decided to replace it. I put in the new battery and the car takes a while to crank the first time, but every other time it works just fine. Now, however, upon each start-up the engine lets the idle drop so low it almost stalls before coming to a stable idle. The idle also dips very low anytime I disengage the clutch and come to a stop. The idle almost always comes back up to normal and stays there. But one time it did dip too low and the engine stalled, thereafter I had the CEL and flashing cruise light. This was never a problem before and I have no engine or power modifications whatsoever. I now sure now they battery itself could cause this, but this is the ONLY thing I have changed.
It could be a bad battery? Test it with a multimeter or take it back to where you purchased it from and have them look at it. Oh, and have them pull the code too.
That or a bad ground... Did you hook the ground cable back up tight? Or perhaps knock another ground cable loose? If so this could have also drained the new battery and/or been the cause orthe old battery slowly loosing power....
Problem has been resolved. Correct size battery and correct ECU reset procedure has fixed all the issues. Thanks for the help guys!
Yeah, a size 26 was listed as well as a size 25. I don't know if that was the problem or not, but I figured more cranking amps the better.